Canopy structures such as those installed at vehicle fuel dispensing service stations typically have flat roofs supported by hollow vertical columns made of corrodible material such as steel. The typical canopy has a fascia around its roof which creates a wind load that is taken into account in the design of the support system. The support columns are often used as conduits for draining water from the flat roof, thus exposing the interior of the columns to corrosive deterioration, which may be entirely internal. Eventually, the canopy support columns may weaken to a dangerous condition resulting in a collapse of the canopy without the owner or operating personnel being aware of their dangerously weakened condition. Such a collapse may occur during a high wind condition with or without rainfall.
It is important to note that there are a very large number of canopies in use today. The task of inspecting all of them on some sort of reasonable schedule is daunting.
Accordingly, there is a need for a way to effectively inspect canopies so that their condition can be properly assessed and repairs timely made.